I wonder if there is a specific word for the joy and sadness on discovering new music/artists.. but so long after the songs were first made that the genre is dead/ the artist is no longer producing or performing.
CivFanatics Forums
Aiken_Drumn
Takhisis
Suomisaundi had its day but isn't dead and things eventually return. Check out the new synthwave/retrowave mood on Youtube (an example here), which proves that the '80s never died, or also the revived Italo-Disco. As for the feeling itself, there probably is an obscure feeling. Nostalgia, maybe?